/Engine/Source/Runtime/Core/Public/Misc/ConfigCacheIni.h
Given a collapsed config value, try and produce an expanded version of it (removing any placeholder tokens).
true if expansion occurred, false if the collapsed and expanded values are equal.
static bool ExpandValue ( const [FString](API\Runtime\Core\Containers\FString) & InCollapsedValue, [FString](API\Runtime\Core\Containers\FString) & OutExpandedValue )